Electric writing machine



Oct. 22 1929. A. LEYvRAz ELECTRIC WRITING MACHINE 2 Sheets-Sheet Filed Dec. l5, 1927 Oct. 22, 1929. A. LEYvRAz 1,732,370

ELECTRIC WRITING MACHINE Filed Dec. 15, 1927 2 sheets-snee: 2

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Patented Oct. 22, 1929 UNITED STATES PATENT OFFICE ANDR LEYVRAZ, OF LAUSANNE, SWITZERLAND, ASSIGNOR TO WALDO MAAS, OF LON-i DON, ENGLAND, AND FRANK GRINSTEAD, OF DURRINGTON, ENGLAND ELECTRIC WRITING MACHINE Application filed December 15, 1927, Serial No.

This invention relates to electrically 0perated type-writing machines of the type comprising a single electro-magnetic motor device producing the striking or impression of all the individual characters of the type, and electro-magnetic devices for selecting the characters the impression of which is to be produced by the said first device the elec tro-magnetic selection devices actuating movable members effecting the actual selection and operation of the type-carrying levers or bars. i

The annexed drawing illustrates an example of construction of the machine.

Fig. 1 is a partial plan view.

Fig. 2 is a vertical longitudinal section on the broken line II-II of Fig. 1.

Figs. 3 and 4t illustrate a detail of the magnetic striking device.

Each of the typescarrying levers or bars 1 is pivoted on a curved rod 2, common to all, and is normally in the horizontal position of rest shown in Fig. 2, but can be brought into the position shown in dotted lines in this ligure where the impression is to be made. To this effect, each lever or bar 1 is provided with a toothed sector 3 gearing with a rack 4 which can move horizontally backwards and forwards in the machine that is to say from right to left or from left to right in Fig. 2 the racks being guided on two semi-circular rods 5, common to all the racks, and passing through guide slots 6 of the latter. The displacement of a rack towards the left in Fig. 2 for the purpose of operating the impression of a character is effected by means of a finger 7 which can move horizontally and vertically, and to which the electro-magnetic impression or striking device 8 imparts a movement to the left (Fig. 2). This .finger comes into om gagement with a nose 9 of the rack a when it is raised by the action of the corresponding and at the other end to an angle bar 12, the4 vertical arm of which is longer than thehorizontal arm thereof.

The angle bar 12 1s made of magnetic ma- 240,276, and in Switzerland December 14, 1926.

terial, of soft iron for example. The electromagnetic selection devices 10 consisting of electro-magnets, each comprise an angle bar 12 the horizontal arm 13 of which supports the core 14 of the coil 15, the vertical part 16 of the angle bar carries the pivot 17 onwhich the armature 18 is pivoted. As can be seen from Fig. 2the gap of the magnetic circuit of the electro-magnet is. relatively small so that the latter functions under good conditions. A spring 19 maintains the armature 1S in its lowered position. Each electro-magnet is fastened to a common support 100 to which is also fixed a bed 29 to which the ends of the conductors of the various `coils 15 are connected and from which lead conductors leading to the operating keys. (not illustrated).

When one ofthe electromagnets 10 attracts its armature 18 the latter lifts the correspending iinger which slides vertically iu a guide bar 21 curved to an are of a circle and supporting all the fingers 7 L The guide bar 21 is fixed to a carriage 22 given horizontal movement by the electromagnetic deviceS. When the finger7 is raised this horizontal movement is communicated to the rack 1 which then produces the impression of the corresponding character. The finger 7 is submitted to the action of a traction spring 2li and its movement is limited by abutment pins 25, it is of square section and moves and is guided in apertures of ,corresponding shape in the guide 21 so that it cannotturn on itself and actsalways with one of its faces on the nose 9.

The carriage 22 is connected rigidly by an arm S()` to a crosspiece 31 constructed of a `magnetic metal and to which are fixed the `movable cores 32 of two solenoids constituting the electro-magnet impression or striking device 8; each of the cores 32 can slide on a guide rod 3a of nonmagnetic metal.

The solenoids 33 contain `fixed cores 37 which are integral with a common block 35 the said fixed cores being provided at the ends adjacent the movable cores 32 with trunconical cavities 36, the cores 32 having similar `cone shaped ends. This arrangement pro vides for the strongest and most rapid attraction of the movable cores.

A traction spring normally maintains the cores 32 separated from the fixed cores 37.

The operation is as follows:

When onev of the keys (not shown) is depressedthe circuit of the corresponding electro-magnet l() and of the Asolenoids 33 is closed.

i The electro-magnet 10 lifts its-armature 18 and causes the finger 7 to rise `so that its up.- per part is opposite the nose 9. As the solenoids 33 then cause the guide 21 to'move from right to left, the finger ,7 strikes the nose,.9 and the lever 1 strikes the paper on the roller (not shown on the drawing). The-impression being effected and the key released the springs 11, 19 and Q4:4 return the various parts to their position ofrest.

As there is only a single electrofmagnetic striking 4or impression device, it canl be .given such dimensions that it will producev an energetic striking. This electro-magnetic:device may have further functions suchas operating the advance of the roller carriagefactuating the linking ribbon, etc. The electro-magnets 10 can however be of very small dimensions, as they have only to furnish slightpower. Further each of them is fixed andthe electromagnetic striking or impression devicein stead of having to displace all the electromagnets 10 has'only the guide-bar .21 tto move and the fingers 7 which it carries, this .guide bar being lighter7 than the squares 12 and the parts which are connectedthereto.

The electro-magnets 10 could be replaced by solenoids and the solenoids 33 by one or more electro-magnets. f

Y Themachine can. be provided with one or morecharacters per type lever.

What I claim as my invention and desire to secure by Letters Patent of the United States 1. In an electrically operated typewritingmachine the combination of a series of type barsa corresponding series of selecting-electro-magnets associated with said bars,v a second electro-magnetic device, a series of slidably mounted ngers associated with said type bars, the said lingers being slidable independently in an axial direction by. said selecting electro-magnets and collectively, in a direction transversely oftheir axes yby said second electro-magnetic device, rackshaving projecting parts on which said fingers in their movement transverselyof their axes operate to move said racks in one direction, toothed specification.

A. LEYVRAZ. 

